Settling process analysis device and method

Abstract

A system and method for monitoring the dynamics of particle motion in a liquid-solid media including the rate of settling of particles, the identification of unsettled particle clouds, and the identification and control of the bed level of settled particles in a slurry within a settler is provided. The system includes an ultrasound transducer and a receiver for detecting echoes from particles in the slurry. The echoes are processed to determine the bed level of the settled particles, the position of unsettled particle clouds, and the rate of settling of the particle clouds.

We claim: 
     
       1. A system for determining the bed level of settled particles in a slurry comprising, an array of 2 to 4 transducers capable of emitting ultrasonic sound waves,   a means for sending said ultrasound signals into a slurry,   a means for receiving echoes caused by the reflection of the ultrasound signals from solid particles in the slurry,   means for converting said echoes to a first set of analog electrical signals;   means for multiplying said first set of analog signals with sine or cos signal to generate a second analog signal;   a means for multiplexing said second analog signals to a means for converting said analog signals to digital signals; and   a data acquisition memory for storing the digital signals for numerical processing.   
     
     
       2. The system of claim 1 further comprising a range phase cancellation memory. 
     
     
       3. The system of claim 2 further comprising a means for controlling said means for multiplexing to provide for selective sampling of portions of said analog signals. 
     
     
       4. The system of claim 1 wherein said numerical processing is by at least one of Doppler method, peak method or moving target method. 
     
     
       5. A device for controlling the bed level of a settling tank comprising the system of claim 1, wherein said system generates electrical signals to control means for depositing chemical additives and slurry additions to a settling tank.   
     
     
       6. A method of claim 1 wherein one or more of the arrays are spaced along the slurry radius. 
     
     
       7. A method of claim 1 wherein the ultrasound transducer array is in the form of a triangle. 
     
     
       8. A method of claim 1 wherein the ultrasound transducer array is in the form of a square.